Sedimentation apparatus



Nov. 22, 1932. c. H. sco'r'r SEDIMENTATION APPARATUS Filed Feb 23, 19324 Sheets-sheaf. 1

INVENTOR CHARLES BY SCOTT ATTORNEY Nov. 22, 1932. c. H. SCOTTSEDIMENTATION APPARATUS Filed Feb; 23, 1932 4 Sheets-Sheet 2 INVENTOR(HA/{LES H.sc0rr BY ATTORNEY Nov. 22, 1932. c. H. sec-r1- SEDIIIENTATIONAPPARATUS Filed Feb. 25. 1932 4 Sheets-Sheet 3 INVENTOR CHARLES H. SCOTTATTORNEY Nov. 22, 1932. c. H. SCOTT SEDIMENTATION APPARATUS Filed Feb.23, 1932 4-Sheets-Sheet 4 INVENTOR CHARLES H. SCOTT ATTORNEY PatentedNov. 22, 1932 UNITED STATES :PATENT OFFICE CHARLES H. SCOTT, OFEDGE-WATER, COLORADO, ASSIGNOR TO THE DORE COMPANY, INC., F YORK, N. Y.,A CORPORATION OF DELAWARE SEDIMENTATION APPARATUS Application filedFebruary 23, 1932. Serial No. 594,441.

This invention relates to sedimentation apparatus of the type ofthickeners or clarifiers in which solids suspended in liquids aresettled to the bottom of the clarifier'by -sedimentation wherein thesettled solids in the ,form of sludge are raked to a central sludgedischarge. The rakes depend from more or less radially extending rakearms which are propelled from a rotatable vertical support.

More particularly, the invention relates to.

the arrangement of the vertical rotatable support mechanism and themeans for rotating said support.

The object of the invention is to devise an arrangement for operatingthe sludge discharge rakes in a manner which avoids the necessity of anyoverhead supporting truss or bridge which has been' considered necessaryheretofore in clarifiers of this type. That is, one object of theinvention is tomake the clarifier more sightly. Another object is to sosimplify the sludge discharge drive mechanism,.that the cost of itsconstruction will be reduced.

To that end the invention includes among other things the provision of acenter shaft, pier or column upstanding from the bottom of the clarifierwhich is used to form the support for a rotatable sleeve or drum whichcarries the sludge dischar e rake mechanism.

At the same time, the p1er is used as a support for the motor devicesfor driving the rotatable drum and;its slud e raking mechanism. This isaccomplishef by providing on the pier a platform or framework from whichthe rotatable drum can depend and from which the motordevices and gearincan be mounted. Alsothe invention inclu es making the center pier hollowand using it as a 2 part of a siphonic central feed to the clarifier.

Thus, the center pier is caused to serve a number of useful purposes.

' I have illustrated in the accompanylng drawings one embodiment of theinvention which is the best of which I am at present in formed. In thesedrawings, Figure 1 is an elevational view, with parts in section andwith parts broken away, of a clarifier showing the invention as appliedthereto; Figure 2 1s a plan view of a clarifier with my 1mroved sludgedischarge driving mechanism; igure 3 is a plan view, with parts insection of the platform from which the rotatable drum depends and onwhich the motor devices are located; Figure 4 is a vertical sec-' tionalview of a detail of the gearing mechanism for the drum in the'manner ofthe drum support; Figure 5 is a partial sectional view with parts brokenaway showing the feed distributing slots; while Figure 6 is adiagrammatic showing of siphonically feeding a plurality of adjacentclarifiers.

In sedimentation devices such as clarifiers, thickcners or sewagedigesters, it is customary to have a tank 11 for holding the liquid fromwhich solids in suspension are to be removed, provided with a side wall12 and a bottom 13. Solids settling to the bottom 13 by sedimentationtake the form of sludge which is raked or impelled by slowly moving rakeblades 14 toward a bottom sludge discharge hopper 15 from which thesludge is removed through a discharge pipe 16. r

The rake blades 14 are usually supported or depend from rake arms 17which extend more or less radially from a central vertical rotatablesupport 18 and the rake arm 17 may be braced by tension rods or baces19.

In the present invention, the vertical support 18 is in the form of adrum, shell, sleeve, structural frame, or cage which encircles a centralcolumn pier or shaft 20 upstanding from the bottom 13 of the clarifiertank. The center pier 20 extends upwardly above 7 the normal liquidlevel 21 in the clarifier and 85 is provided with a platform 22supported from a stationary-framework 45 forming substantially anextension of the pier. To this platform or framework extends a bridge 23from the periphery orwall 12 of the clarifier to provide a walkway forthe 0 erator to the platform 22 to'inspect the mec anism mountedthereon. The bridgcor' walkway 23 may be used to house the necessaryelectric wiring 24 to convey power to the operating mechanism and it mayor may not also be used to support a feed launder for the incomingliquid to be treated in the clarifier.

The feed under some circumstances may be brought in by a radial feedlaunder so that it I is fed to the clarifier centrally thereof, or underother circumstances the feed to the clarifier ma be arranged periherally of the clarifier. I Iowever, my pre erred form of feed is bymeans of an inverted siphon 25 extending upwardly through the pier 20,which in pulley or sprocket 30; belt or chain 31; and

pulley or sprocket 32; and a shaft 34 suitably supported on theframework which is r0- vided with a worm gear 35 meshing wit ahorizontal gear 36 carried by vertical shaft 37. This shaft has keyed toit a gear 38 meshing with a bull or ring gear 39, from which isdependingly supported the drum 18, which is preferably secured to thegear 39 by means of a flanged turn-table or ring 40. The motor 28 andspeed reducer 29 may be suitably housed by casing 41, and the pulley 32may also be housed by casing 42. A further casing 43 may protect thehorizontal gear 36 while the shaft 37 may be suitably housed andjournaled at 44. i

The turn-table 40, carrying the drum 18, is supported from the frameworkor turntable base 45 (which also includes journal 44 and flange 60)secured in position on the pier 20 4 in any suitable manner. The base 45also supports the platform 22. The shaft may have lubricatingconnections such as at 46. The drum 18 may be suspended from theturntable 40 by means of channel-irons 47 spaced apart to form theslotted openings 27. These channel-irons have flanges 48. One or more ofthe channel-irons may be extended as at 49 to reenforce the drum' 18against thrust thereon exerted by the sludge raking mechanism. 7

Under certain circumstances, it is desirable to indicate any abnormalload which may come on the sludge discharge mechanism so for thatpurpose there is applied at the end of the shaft 34 an overload alarmdevice 50. This is arranged by having the shaft 34 mounted for slightlongitudinal movement in its bearings 51 and 52,.but a spring 53 isprovided in a supporting frame 54 which normally tends to preventlongitudinal displacement of the shaft 34. If an abnormal load comes onthe drive mechanism, the shaft 34 will be displaced longitudinallyagainst the pressure of the spring 53 and this displacement of the shaftoperates a pivoted pointer 55 which shows on a scale 56 that the pointerhas passed the position of normal operation. The pointer may also beused to Operate a visible or audible signal to the operator, thatabnormal conditions exist.

Liquid from which suspended solids have been settled overflows into aperipheral outlet 57 after first getting past a bafile or weir 58 andthen flows from the efiluent launder 57 through the outlet pipe 59. 60indicates a bracket arrangement forming part of the turntable base orframework 45, which suphollow portion 62 forming one leg of a siphon 25,and connecting to the hollow portion the remaining portion of the siphon25. The siphon is of course fed from a source of supply of the liquid tobe treated in a clarifier located higher than the liquid level in theclarifier. The liquid from the leg 62 of the siphon within the pier 20exits therefrom through slotted openings 26 in the pier. The slottedopenings 27 in the drum 18 are alignable with the openings 26 to enablethe feeding material to pass through the revoluble drum 18 to be treatedin the clarifier.

Where several clarifiers are to be used, they can be arranged asdiagrammatically shown in Fig. 6 wherein 64, 65, 66 and 67 representclarifiers, each provided with a.

hollow central pier 20. 68 indicates the channel containing liquid to'betreated in the clarifiers leading to a disturbing basin 69 from which asiphonic feed 25' leads to each clarifier. A valve or other flowcontrolling device 70 is provided for each siphonic feed whereby feedfrom the basin 69 can be selectively supplied to any or all of theclarifiers. As the liquid level in the basin 69 is maintained above theliquid level ,in the clarifiers, it furnishes suflicient hydrostatichead to siphon the feed from the basin into the clarifiers.

Operation The liquid with its solids in suspension to be clarifiedorthickened by sedimentation is flowed into the sedimentation tank 11 ina I continuous manner and the carified liquid is flowed therefrom asefiluent in a continuous manner. Solids settling out of the liquid fallto the bottom of the clarifier in the form of sludge and are collectedby blades 14 which are moved by means of the rake arm 17 which arerotated by the central vertical rum 18 equipped with ed on the turn-tale base or framework supported on the central pier. The drum 18 dependsfrom a turn-table 40 deriving its support from the bracket arrangement60 forming a part of the turn-table base 45 and is preferably supportedon an anti-friction device 61. The turn-tables 40 from which the drum 18depends is provided with a bull ring or gear 39 which is driven by meansof suitable gearing from the motor 28.

Operation of the motor 28, through the speed reducer 29, shaft 34 andworm gear 35, causes gear 36 to rotate vertical pinion 37 with its gear38, and gear 38 meshing with bull gear 39 rotates the turn-table 40 fromwhich the drum 18 depends. Rotation of drum 18 with its rake arms andrakes causes settled sludge to be conveyed to the sludge discharge 15.

This arrangement of center pier, center drive for the sludge dischargemechanism also lends itself to the central siphonic feed to theclarifier. The feed from a suitable source of supply which is at a levelabove the liquid level in the clarifier flows through the siphon 25 upthrough the hollow central pier 20 and out therefrom through the slots26, the height of the supply above the liquid level in the clarifierbeing suflicient to provide the necessary hydrostatic head. It will berecalled that the drum 18 revolves, so slots 27 are provided in itwhich, during its rotation, intermittently register with the slots 26 inthe pier extension 45 in order that the feed from the s ots 26 can passthrough the drum into the clarifier through the slots 27 Thisarrangement is found to be doublv advantageous, in that the rotation ofthe drum has a helpful distributing effect upon the feed passing throughthe slots 27 therein. The fins or flanges 48 associated with the slots27 in the drum 18 aid in difi'using the sewage flowing through the slotsinto the body of liquid in the clarifier. Where it is desired to feedsiphonically to a group of this can be done by the arrangement shown inFigure 6 and described above.

It will thus be seen that the invention provides a neat and compactarrangement for driving the sludge discharge mechanism of a thickener,clarifier or digester in a manner that is cheap to build, is attractivein appearance and is practically fool-proof. The embodiment described isshown in an illustrative sense for the purpose of showing in what-mannerthe invention ma be carried out and not in a limiting sense or obviouslymany modifications may be made in the embodiment shown herein withoutdepartin from the spirit and scope of the appended claims.

I claim:

1. A sludge discharge operating mechanism for a sedimentation tankcomprising an upstanding pier in the tank, a flanged ring rotatablymounted on said pier, a drum depending from said ring, a motorsupportedfrom said pier, a driving gear connection between said motorand said ring for rotating said ring and its depending drum, and sludgerakes operated by rotation of said drum.

2. Sedimentation apparatus havin a tank with a sludge discharge, sludgedisc arging rakes; and means for operating said rakes comprising a pier,a rotatable drum supporting said rakes, a motor, and a drivingconnection between said motor and said drum, and a stationary frame workon said pier having the combined function of supporting said motor, saiddriving connection and said drum.

3. Sedimentation apparatus having a tank with a sludge discharge, sludgedischarging rakes; and means for operating said rakes comprising a pier,a framework arrangement forming an extension of said pier mountedthereon, a drum carrying said rakes rotatably depending from saidframework, a motor and a driving connection between said motor and drum,said framework supporting said motor, said driving connection and saiddrum.

4. Sedimentation apparatus having a tank with a sludge discharge, sludgedischarging rakes; comprising a pier, a framework arrangement thereon, adrum carrying said rakes rotatably depending from said framework, amotor, a worm gear driven thereby, a gear driven by said worm gear, avertical pinion secured to said gear passing through said framework, agear thereon below said framework, and a bull gear on said drum belowsaid framework with which meshes said gear on said pinion below saidframework.

5. Sedimentation apparatus havin a tank -with a sludge discharge, sludgedisc arging rakes, a central feed for said tank; and combined means foroperating said rakes and housing said feed comprising a hollow pier,

and means for operating said rakes ILL,

a rotatable drum supporting said rakes, a

ment supported from and encircling said I pier, sludge rakes operated byrotation of said drum, a ring gear associated with said drum, astationary motor supported from said pier, and a gear connection betweensaid stationary motor and said ring ear for r0- tating said drum throughthe me ium of said ring ear.

7. sedimentation tank havin a hollow center pier through which liquid isdischarged into the tank, a driven rotatable drum encircling said pier,sludge raking devices associated with said drum, and means fordistributing liquid discharging from said pier comprising slots in saiddrum.

8. A sedimentation tank having a hollow center pier through which liquidis discharged into the tank, a driven rotatable drum encircling saidpier, sludge raking devices associated with said drum, and means fordistributing liquid discharging from said pier comprising slots in saiddrum and fins extending substantially radially from said drum.

9. A sedimentation tank having a hollow center pier through which liquidis fed to the tank, a slotted extension on said pier through whichliquid is discharged from the pier into the tank, a driven rotatabledrum encircling said pier, sludge raking devices associated with saiddrum, and means for gassing radially through said drum liquid ischargingfrom said slotted extension.

10. Apparatus of the type described comprising a sedimentation tank, anupstanding pier in said tank, a rotatable element supported from andencircling said pier, sludge rakes operated by rotation of said element,a ring associated with said element, a platform mounted from said pier,a stationary motor supported from said platform, and a drive connectionbetween said motor and said ring for rotating said drum through themedium of said ring. V

In testimony whereof I have afiixed my signature to this specification.,7 CHARLES H. SCOTT.

